The present invention relates generally to the field of support devices for supporting print screens during application of emulsion or other coating materials, and, more specifically, to a support device designed especially for supporting print screens in a manner which permits 360 degree rotation for the screen around two different axes, as well as permitting the operator to adjust the height at which the screen is supported, for optimal comfort and convenience in use of the device.
It is well known in the screen printing industry that prior to use of a screen for printing it is usually necessary to condition the screen by applying a coating of liquid emulsion. The coating material may be applied with a brush, but ordinarily is sprayed over the screen to apply an even layer over the entire screen surface, on one or both flat side surfaces of the screen. The screen to be prepared is ordinarily stretched taught over a rigid rectangular frame, which frame with the screen attached is later transferred to the printing press for use in printing piece goods such as "t-shirts" or other textiles. The frames used in such printing presses may vary somewhat in size and shape, within the parameters allowed by a particular printing press, or as required for a certain job.
Because a different print screen is prepared for each design and/or color to be printed, it is clear that a great number of screens may be required by even a relatively small print shop, and particularly by shops of the type which cater to large and varied crowds, and/or by manufacturers which provide pre-made screens to specialty shops, such as t-shirt stores. The process of coating the framed print screens for further use necessarily becomes tedious when more than a few screens must be prepared.
As the emulsion coating process is generally done manually, such tedium increases the chance that the coating may be applied incompletely or unevenly. This risk increases with operator fatigue, which naturally occurs with preparation of multiple screens which must be turned and viewed from various angles to ensure complete coating. Improper height of the screens being so laboriously coated can require the worker to operate in unnatural or inconvenient body positions, resulting in pain to the worker's back, shoulders, neck, etc. Such worker discomfort can result in screens which are less than ideally coated with emulsion, and can thus eventually lead to printed goods of less than the best quality.
Previously, although a variety of supports for flat work pieces of various types were conceived, none of those supports were suitable for the goals of the present invention. No support devices were known which were designed specifically for use as multi-directional rotatably adjustable supports for print screens for coating or other treatment thereof. Rather, the screen emulsion coating process was done in a variety of haphazard ways, with the screen propped up against a wall or laid flat, horizontally on a table or between the edges of two tables or other supports, such as saw horses. These methods necessarily had drawbacks, as they could become uncomfortable for a worker who was forced to bend over repeatedly, or required to stand for extended periods of time to coat numerous screens.
Also, in addition to worker fatigue, because of inconsistent, imperfect lighting and screen position, the coating applied in known manner was sometimes not well applied, eventually resulting in printing of inferior quality. Furthermore, the known coating methods were messy, as it was necessary for the worker to occasionally touch the wet screen frame to reposition it for application of emulsion to a different surface.
Although the new support device is conceived with the particular purpose of print screen coating in mind, as will become clear with the description hereafter, other very useful purposes can be imagined for which device 10 is suitably adapted, and which uses would be considered to be well within the scope of this invention, particularly when there is involved support of a flat rectangular piece which is to be attended to on both flat sides thereof, and when it is preferred to be able to adjust the height of work piece at any time during the treatment process.
Accordingly, it is among the objects of the present invention to provide a support device for flat work pieces of various sizes having rigid edges or which are connected to a rigid frame, which support device is adapted for facile, pivotal touch-free adjustment of the position of the work piece by 360.degree. around a central axis of the work piece supported upon the device, spacedly from the vertical support member thereof. The new support device is also structured to permit the work piece to be rotatable at least 180.degree. and even 360.degree. or more around an axis extending substantially horizontally and radially from the device, and to also be reliably retained in a variety of preselected angled positions on the support device.
It is further among the objects of the present invention that the new support device be capable of vertical adjustment in a quick and facile manner so as to permit the work piece to be supported at a height which is ergonomically preferred by any particular user. The device of the present invention is further expected to be optionally mounted on casters, slides, rails, or other suitable structure for making the device easily movable on a floor or other support surface so that the work piece can be attended to in an environment with optimal lighting, air movement, space, and other ambient conditions.
It is still further among the objects of the present invention that the support device having the features indicated be suitable for attachment of a light to enhance the user's viewing of the work piece and of the coating being applied or other treatment to which the work piece, such as a print screen, is being submitted.
It is also among the objects of the present invention having the features mentioned that the new support device be of uncomplicated, straight-forward construction of known materials and thus economical to manufacture and to maintain, and that it be facile to assemble and use by individuals with little or no training, even when provided with optional automatic adjustment and lighting features.
Accordingly, in furtherance of the above objects and advantages, the present invention is, briefly, a device for adjustably supporting a print screen during application of emulsion. The device includes an upright stand assembly which is adapted to permit vertical adjustment of the position of a print screen mounted on a screen frame support rack on the device. A screen frame support rack is rotatably connected to the stand assembly in such manner as to permit selective vertical rotation of the entire screen frame support rack by up to at least 180.degree. around a first axis, which first axis is substantially horizontal and extends radially, outwardly from longitudinal axis of the upright stand. The screen frame support rack is adapted to support the print screen in such a manner as to permit selective rotation of the print screen around a second axis of rotation to any angle up to at least 180.degree., the second axis of rotation being a central axis of the print screen; so thath the position of a print screen supported on the device can be selectively adjusted both vertically and rotationally, the rotational adjustments being available around two different axes.
These and other advantages and objects of the invention will be in part apparent and in part pointed out hereinbelow.